CN106027046A - Atomic-clock-based high-purity reference source generation method and system - Google Patents
Atomic-clock-based high-purity reference source generation method and system Download PDFInfo
- Publication number
- CN106027046A CN106027046A CN201610657357.6A CN201610657357A CN106027046A CN 106027046 A CN106027046 A CN 106027046A CN 201610657357 A CN201610657357 A CN 201610657357A CN 106027046 A CN106027046 A CN 106027046A
- Authority
- CN
- China
- Prior art keywords
- frequency
- crystal oscillator
- signal
- atomic clock
- phase
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 13
- 239000013078 crystal Substances 0.000 claims abstract description 48
- 230000015572 biosynthetic process Effects 0.000 claims description 10
- 230000000694 effects Effects 0.000 claims description 3
- 230000007774 longterm Effects 0.000 abstract description 7
- 238000009499 grossing Methods 0.000 abstract 1
- 238000003786 synthesis reaction Methods 0.000 description 7
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000032683 aging Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 230000003412 degenerative effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03L—AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES
- H03L7/00—Automatic control of frequency or phase; Synchronisation
- H03L7/26—Automatic control of frequency or phase; Synchronisation using energy levels of molecules, atoms, or subatomic particles as a frequency reference
Landscapes
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
Abstract
The invention relates to a frequency source technology and discloses an atomic-clock-based high-purity high-frequency reference source generation method. The method includes the following steps that an output signal of a crystal oscillator is subjected to N frequency demultiplication and then subjected to phase discrimination in a phase discriminator with an atomic clock signal, and after a generated error voltage is subjected to smoothing through a loop filter, a direct current error signal is generated; the direct current error signal controls the tuning end of the crystal oscillator, and the output frequency of the crystal oscillator is stabilized to be N times that of the atomic clock signal. The invention further discloses an atomic-clock-based high-purity high-frequency reference source generation system. Compared with a traditional atomic-clock reference signal, the frequency of a reference source generated through the method and system is improved by 5-10 times, and phase noise of the reference signal is increased by 10 Db or above; compared with a traditional crystal oscillator (temperature compensation/constant temperature), indexes such as frequency accuracy and long-term stability are increased by three numerical levels or above, and a frequency source product is more accurate and longer in life cycle.
Description
Technical field
The present invention relates to rf frequency synthetic technology, a kind of high-purity a reference source production method based on atomic clock and system, provide precision height, the high-purity reference signal of good stability for system.
Background technology
Frequency synthesis has Low phase noise by one exactly, the signal processing such as a reference source of high accuracy and the aggregative indicator such as high stability mixing, frequency multiplication, frequency dividing or phaselocked loop on oversampling circuit carry out adding in mathematical meaning, subtract, the four arithmetic operation such as multiplication and division, produce the frequency source that there is same degree of accuracy in a large number with degree of stability.The basis of frequency synthesis is a reference source, and the height of a reference source index directly determines the height of frequency synthesized signal index, and almost all of high-tech application system is required for high-precision reference signal and supports.
The phase noise specifications of frequency synthesis is followed 20logN and is deteriorated theory, and frequency multiplication times N is the biggest, and phase noise deteriorates the biggest, therefore selects the reference signal that frequency is higher, has the biggest advantage to frequency synthesis.
Crystal oscillator (temperature compensation/constant temperature) has the features such as frequency height, low, the low cost of phase noise, use the most in a large number, this benchmark possesses the frequency range of 10MHz-200MHz, in order to improve the index of making an uproar mutually of frequency synthesis, reduce N value as far as possible, and combine crystal oscillator (temperature compensation/constant temperature) self-characteristic, it is typically chosen 50MHz, 100MHz as reference signal, the phase noise specifications of such a reference source is the highest,-150dBc/Hz@1kHz can be better than, but its frequency accuracy, temperature stability are poor, typically can only achieve 10-7Magnitude, and As time goes on, crystal oscillator (temperature compensation/constant temperature) there is also aging, general ageing rate 10-6-10-7/ year.
If frequency accuracy and degree of stability are had higher requirement, atomic clock is best selection, and atomic clock utilizes between the internal energy level of atom or ion jump frequency as reference, locking crystal oscillator or laser frequency, thus the device of outputting standard reference frequency.The frequency of atom output is generally 10MHz, and frequency accuracy can reach 10-11Above, temperature stability is better than 10-10, long-term stability reaches 10-9/ 10 years, compared to crystal oscillator (temperature compensation/constant temperature), such index all improved more than three orders of magnitude.But atomic clock there is also shortcoming, phase noise specifications is poor, generally-140dBc/Hz@1kHz, and additionally output frequency is low, and when carrying out frequency synthesis, frequency multiplication number of times is relatively big, deteriorates the phase noise of output signal further.
Along with developing rapidly of modern electronic equipment, the long-term stability of frequency source and short-term stability are proposed higher requirement, and the frequency synthesis on the basis of tradition crystal oscillator (temperature compensation/constant temperature) or atomic clock is respectively arranged with quality, is all difficult to take into account simultaneously；Therefore the development in high-purity high frequency standard source can meet high accuracy, the use demand of high stability that a reference source is promoted by system day by day.
Summary of the invention
It is respectively arranged with quality for frequency source of the prior art, is all difficult to the technical problem simultaneously taken into account, the invention discloses a kind of high-purity a reference source production method based on atomic clock and system.
Technical scheme is as follows:
The invention discloses a kind of high-purity high frequency standard source generating method based on atomic clock, it specifically includes below step: the output signal of crystal oscillator carries out phase demodulation with atomic clock signal after Fractional-N frequency in phase discriminator, after the error voltage produced is filtered by loop filter, produce DC error signal；DC error signal controls the tuning tip of crystal oscillator, makes crystal oscillator output frequency stablize the atomic clock signal at N times.
Further, said method is particularly as follows: atomic clock signal is as the reference signal of phase discriminator, reference signal input phase is θ 1 (t), the signal of crystal oscillator output phase place after Fractional-N frequency is θ 2 (t), θ 1 (t) and θ 2 (t) enters phase discriminator and carries out phase bit comparison, produce error phase θ e (t), corresponding error voltage Ud (t) is produced by error phase, error voltage controls voltage UC (t) through being filtrated to get of loop filter F (p), control voltage UC (t) to be added on crystal oscillator be allowed to produce frequency shift (FS), under the effect of error voltage Ud (t), the 1/N of crystal oscillator output frequency gradually draws close to reference incoming frequency.
Further, above-mentioned crystal oscillator is temperature compensation/constant-temperature crystal oscillator.
Further, the bandwidth of above-mentioned loop filter less than several Hz to what time Hz.
The invention also discloses a kind of high-purity high frequency standard source based on atomic clock and produce system, it specifically includes atomic clock, phase discriminator, loop filter circuit and crystal oscillator；Described atomic clock, phase discriminator, loop filter circuit and crystal oscillator sequentially connect formation closed loop control；The output signal of described crystal oscillator carries out phase demodulation with atomic clock signal after Fractional-N frequency in phase discriminator；Described atomic clock is as the reference signal of phase discriminator；After the error voltage that phase discriminator produces is filtered by loop filter, produce DC error signal, control the tuning tip of crystal oscillator.
By using above technical scheme, the invention have the benefit that the present invention utilizes phase-locked principle, phase noise beyond output signal loop bandwidth is decided by of crystal oscillator (temperature compensation/constant temperature) itself, and the long-term stability of output signal, temperature stability are all decided by the atomic clock as reference simultaneously.The so existing preferable long-term stability of this reference signal, temperature stability has possessed again preferable phase noise.
Use a reference source that the present invention produces, compared to traditional atomic clock reference signal, frequency improves 5 ~ 10 times, and the phase noise of reference signal own improves more than 10dB, comprehensive two aspect factors, improve more than 15dB using a reference source that the present invention produces as the phase noise of the frequency synthesizer of reference；Compared to traditional crystal oscillator (temperature compensation/constant temperature), the index such as frequency accuracy, long-term stability improves more than three orders of magnitude, makes frequency source product more accurate, and life cycle is longer.
Accompanying drawing explanation
Fig. 1 is the circuit of high-purity high frequency standard source generating method based on atomic clock.
Fig. 2 is the circuit structure of loop filter circuit.
Detailed description of the invention
Below in conjunction with Figure of description, describe the detailed description of the invention of the present invention in detail.
The circuit diagram of high-purity high frequency standard source generating method based on atomic clock as shown in Figure 1, the invention discloses a kind of high-purity high frequency standard source generating method based on atomic clock, it specifically includes below step: the output signal of crystal oscillator carries out phase demodulation with atomic clock signal after Fractional-N frequency in phase discriminator, after the error voltage produced is filtered by loop filter, produce DC error signal；DC error signal controls the tuning tip of crystal oscillator, makes crystal oscillator output frequency stablize the atomic clock signal at N times.
Present invention utilizes the operation principle of phaselocked loop, phaselocked loop is the degenerative error control system of phase place, using atomic clock as the benchmark Fref of reference signal, reference signal input phase is θ 1 (t), the signal of adjustable crystal oscillator output phase place after Fractional-N frequency is θ 2 (t), θ 1 (t) and θ 2 (t) enters phase discriminator and carries out phase bit comparison, produce error phase θ e (t), corresponding error voltage Ud (t) is produced by error phase, error voltage controls voltage UC (t) through being filtrated to get of loop filter F (p), control voltage to be added on VCXO be allowed to produce frequency shift (FS), follow the tracks of frequency input signal.If incoming frequency is fixed, under the effect of error voltage Ud (t), the 1/N of output frequency gradually draws close to incoming frequency, reach equal both once, meet some requirements (scope of this threshold value can set the most flexibly), loop just can settle out, thus reaches loop-locking.Now, the output frequency of crystal oscillator is N Fref.
Fig. 2 is the circuit structure of loop filter circuit.Continue to use the topological structure of conventional loop filter, the design that it is critical only that loop filter parameters that the present invention realizes, the bandwidth of conventional loop filter is generally tens kHz to hundreds of kHz, in the present invention in view of crystal oscillator phase noise to output contribution, loop filter bandwidth is designed as a few Hz, in order to realize the least loop bandwidth, during circuit design, have employed the form that multiple electric capacity is in parallel, obtain required large bulk capacitance with this.
In the present invention, the parameter of loop filter is as follows:
R1 ~ R4 is generally 100 ~ 2K Ω；
R5=R6
Generally 1K ~ 20K Ω；
R7 is generally 100 ~ 2K Ω；
Total capacitance in parallel for C1 ~ C5 is 1 ~ 20 μ F；
C6 ~ C10 is the balance end of C1 ~ C5, and the two capacitance is the most identical；
Total capacitance in parallel for C11 ~ C19 is 10 ~ 100 μ F；
C21 ~ C29 is the balance end of C11 ~ C19, and the two capacitance is the most identical；
C30, C31 are generally 10P ~ 200P, and the two capacitance is the most identical；
C32 is generally 1n ~ 10nF.
The present invention is using the atomic clock of high stability as reference signal, and adjustable crystal oscillator (temperature compensation/constant temperature) is as output.
Such as, using the high steady a reference source of the 50MHz that the present invention produces, frequency synthesizer based on this reference source is compared to tradition crystal oscillator as the implementation of reference, and frequency accuracy improves 104Times, temperature stability, long-term stability all improve 103Times；Compared to atomic clock reference signal, the phase noise of the frequency source synthesizer of this project improves about 17dB, preferably meets engineer applied needs.
The invention also discloses a kind of high-purity high frequency standard source based on atomic clock and produce system, it specifically includes atomic clock, phase discriminator, loop filter circuit and crystal oscillator；Described atomic clock, phase discriminator, loop filter circuit and crystal oscillator sequentially connect formation closed loop control；The output signal of described crystal oscillator carries out phase demodulation with atomic clock signal after Fractional-N frequency in phase discriminator；Described atomic clock is as the reference signal of phase discriminator；After the error voltage that phase discriminator produces is filtered by loop filter, produce DC error signal, control the tuning tip of crystal oscillator.
The coefficient gone out given in the above embodiments and parameter; it is available to those skilled in the art realize or use invention; invention does not limit and only takes aforementioned disclosed numerical value; in the case of the thought without departing from invention; above-described embodiment can be made various modifications or adjustment by those skilled in the art; thus the protection domain of invention is not limited by above-described embodiment, and should be the maximum magnitude meeting the inventive features that claims are mentioned.
Claims (4)
1. a high-purity high frequency standard source generating method based on atomic clock, it specifically includes below step: the output signal of crystal oscillator carries out phase demodulation with atomic clock signal after Fractional-N frequency in phase discriminator, after the error voltage produced is filtered by loop filter, produce DC error signal；DC error signal controls the tuning tip of crystal oscillator, makes crystal oscillator output frequency stablize the atomic clock signal at N times.
2. high-purity high frequency standard source generating method based on atomic clock as claimed in claim 1, it is characterized in that described method particularly as follows: atomic clock signal is as the reference signal of phase discriminator, reference signal input phase is θ 1 (t), the signal of crystal oscillator output phase place after Fractional-N frequency is θ 2 (t), θ 1 (t) and θ 2 (t) enters phase discriminator and carries out phase bit comparison, produce error phase θ e (t), corresponding error voltage Ud (t) is produced by error phase, error voltage controls voltage UC (t) through being filtrated to get of loop filter F (p), control voltage UC (t) to be added on crystal oscillator be allowed to produce frequency shift (FS), under the effect of error voltage Ud (t), the 1/N of crystal oscillator output frequency gradually draws close to reference incoming frequency.
3. high-purity high frequency standard source generating method based on atomic clock as claimed in claim 1, it is characterised in that described crystal oscillator is temperature compensation or constant-temperature crystal oscillator.
4. a high-purity high frequency standard source based on atomic clock produces system, it is characterised in that specifically include atomic clock, phase discriminator, loop filter circuit and crystal oscillator；Described atomic clock, phase discriminator, loop filter circuit and crystal oscillator sequentially connect formation closed loop control；The output signal of described crystal oscillator carries out phase demodulation with atomic clock signal after Fractional-N frequency in phase discriminator；Described atomic clock is as the reference signal of phase discriminator；After the error voltage that phase discriminator produces is filtered by loop filter, produce DC error signal, control the tuning tip of crystal oscillator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610657357.6A CN106027046A (en) | 2016-08-12 | 2016-08-12 | Atomic-clock-based high-purity reference source generation method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610657357.6A CN106027046A (en) | 2016-08-12 | 2016-08-12 | Atomic-clock-based high-purity reference source generation method and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106027046A true CN106027046A (en) | 2016-10-12 |
Family
ID=57135146
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610657357.6A Pending CN106027046A (en) | 2016-08-12 | 2016-08-12 | Atomic-clock-based high-purity reference source generation method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106027046A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109302181A (en) * | 2017-07-24 | 2019-02-01 | 恩智浦有限公司 | Oscillator calibration system |
| CN110989326A (en) * | 2019-12-26 | 2020-04-10 | 中国计量科学研究院 | Local high-precision time frequency real-time comprehensive device |
| CN111953345A (en) * | 2020-07-06 | 2020-11-17 | 南京熊猫电子股份有限公司 | High-stability low-phase noise standard frequency processing method and system |
| CN112583404A (en) * | 2020-11-12 | 2021-03-30 | 北京遥测技术研究所 | High-precision time-frequency reference source of navigation enhancement system |
| CN115470918A (en) * | 2022-09-26 | 2022-12-13 | 量子科技长三角产业创新中心 | Time frequency signal generating device, quantum measurement and control system and measurement and control method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102769462A (en) * | 2011-05-06 | 2012-11-07 | 成都天奥电子股份有限公司 | Direct digital frequency phase-locked frequency multiplier circuit |
| CN205249184U (en) * | 2015-11-19 | 2016-05-18 | 江汉大学 | Frequency synthesizer |
-
2016
- 2016-08-12 CN CN201610657357.6A patent/CN106027046A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102769462A (en) * | 2011-05-06 | 2012-11-07 | 成都天奥电子股份有限公司 | Direct digital frequency phase-locked frequency multiplier circuit |
| CN205249184U (en) * | 2015-11-19 | 2016-05-18 | 江汉大学 | Frequency synthesizer |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109302181A (en) * | 2017-07-24 | 2019-02-01 | 恩智浦有限公司 | Oscillator calibration system |
| CN109302181B (en) * | 2017-07-24 | 2023-09-01 | 恩智浦有限公司 | Oscillator Calibration System |
| CN110989326A (en) * | 2019-12-26 | 2020-04-10 | 中国计量科学研究院 | Local high-precision time frequency real-time comprehensive device |
| CN111953345A (en) * | 2020-07-06 | 2020-11-17 | 南京熊猫电子股份有限公司 | High-stability low-phase noise standard frequency processing method and system |
| CN112583404A (en) * | 2020-11-12 | 2021-03-30 | 北京遥测技术研究所 | High-precision time-frequency reference source of navigation enhancement system |
| CN115470918A (en) * | 2022-09-26 | 2022-12-13 | 量子科技长三角产业创新中心 | Time frequency signal generating device, quantum measurement and control system and measurement and control method |
| CN115470918B (en) * | 2022-09-26 | 2024-08-23 | 量子科技长三角产业创新中心 | Time-frequency signal generating device, quantum measurement and control system and measurement and control method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106027046A (en) | Atomic-clock-based high-purity reference source generation method and system | |
| US7973612B2 (en) | Supply-regulated phase-locked loop (PLL) and method of using | |
| CN106209093B (en) | A kind of digital fractional frequency-division phase-locked loop structure | |
| KR100682279B1 (en) | Adaptive frequency calibration apparatus of frequency synthesizer | |
| EP3931968B1 (en) | Generator and method for generating a controlled frequency | |
| KR20220011113A (en) | Circuit and method for determining the ratio between two frequencies | |
| TW201531035A (en) | Charge pump calibration for dual-path phase-locked loop | |
| CN108259035B (en) | Reference clock determining method and device | |
| CN101483430A (en) | Phase locked loop with adaptive filter for DCO synchronization | |
| EP3931966B1 (en) | Generator and method for generating a controlled frequency | |
| CN102611441A (en) | Ultralow phase noise reference signal generating device for frequency synthesizer | |
| CN102412837B (en) | Method for realizing low spurious small-step frequency synthesizer | |
| CN205356307U (en) | Frequency synthesizer of short wave receiver | |
| CN101498761B (en) | Test method for step response performance of phase-locked loop system | |
| CN202475398U (en) | Ultra-low phase noise reference signal generating device used for frequency synthesizer | |
| CN108667455A (en) | Locking loop with the reference signal by not modifying oscillator offer | |
| US20140354262A1 (en) | Lock detector for digital phase-locked loop | |
| CN103326717B (en) | A kind of rubidium clock scan capture secondary locking method | |
| CN201113979Y (en) | High-frequency high precision locking phase constant temperature crystal oscillator | |
| CN103916124B (en) | A kind of injection locking frequency dividing structure of band automatic frequency verifying function | |
| CN103501174A (en) | Low-noise reference signal generator and signal generation method | |
| CN201869161U (en) | High-frequency high-stability phase-locking OCXO | |
| CN102420606B (en) | Low phase-noise and small step-frequency synthesized realizing method | |
| CN203775188U (en) | Clock generator | |
| CN104467825B (en) | A method of based on Clean-up digital servo-control loop self-adaptive quick lock in crystal oscillator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20161012 |
|
| RJ01 | Rejection of invention patent application after publication |